If your phone was SIM-unlocked (using a code or another procedure), you must keep the nv_data.bin file:
adb shell busybox mount -o remount,rw /factory adb pull /factory/ adb shell "cat /data/radio/nv_data.bin > /factory/nv_data.bin" adb shell "cat /data/radio/nv_data.bin.md5 > /factory/nv_data.bin.md5"
Follow the procedure described in: HeimdallRecoveryInstallation